Elevator.



M. O. SGHWAB.

ELEVATOR.

APPLICATION FILED 001:. 24, 1910.

1,098,845, Patented June 2, 1914.

itibzeasew/ xzzerzzaz UNITED STATES PATENT OFFICE.

MARTIN G. SCHWAB, OF CHICAGO, ILLINOIS.

ELEVATOR.

To all whom it may concern Be it known that l, MARTIN C. Sonwan, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Elevators, of which the following is a specification.

My invention relates to improvements in elevators and more particularly to safety devices therefor, whereby the motive power employed for moving the elevator is automatically disabled upon the occurrence of an abnormal condition.

One of the objects of my invention is to provide a means whereby the motive power, employed to move the elevator, is disabled, or shut off, upon the occurrence, by the cage or the counterweights, traveling beyond the terminals of their respective normal paths.

In elevators wherein the cage is raised by means of cables, they in course of time become abnormally stretched to such an extent that the counterweight will, in many instances, reach the lower end of its path before the cage reaches the upper terminal of its path, and in the class of elevators known as traction elevators in which a single continuous cable is employed, and its lifting or tractive power is effected by friction of the cable on the surfaces of sheaves due to the weight of the cage on one side of the sheave and the counterbalance on the other side, this is especially true. It also follows that should the cage for any reason tend to travel above its normal upper terminal, or the cable be so stretched that it can not reach its upper terminal, the counterweight prematurely reaching a point of rest at its lower terminal of travel, the friction tension on the sheaves would be released to such a degree as to cause the cage to continue to bob up and down, thereby straining the cables unduly and possibly unshipping the cables from the sheaves. To overcome these objections, I have devised a safety de vice whereby the motor operating the elevator is automatically disabled or stopped at any time when the counterweight prematurely reaches its lower limit of travel.

In the drawing, Figure 1 shows the device in elevation; and Fig. 2 is a similar view showing the device as seen at right angles from Fig. 1.

In both of the views, the same reference characters indicate similar part-s.

5 is an elevator cage, adapted for vertical Specification of Letters Patent.

Application filed October 24, 1910.

Patented J une 2, 1914.

Serial No. 588,679.

movement within the shaft or well 6. To the upper end of the cage, as at 7 a cable, 8, is attached. An electric motor 9 drives .a shaft 10 to which is secured a series of sheaves 11, 11, 11 and. 11. A stationary stud or jack shaft 12 is fixed to bearing support 13. Loosely mounted on the stud shaft 12 are a series of sheaves 14, 1-1, 14". The cable 8 is wound around the sheaves l1 and 14 respectively, as clearly shown, its terminal end leading from sheave 10 to the counfer-balance weight 15.

So far the structure described corresponds with traction elevators generally in use.

My invention consists in means for looking th Weight in its abnormal. position and for simultaneously operating a circuit-opening switch to shut the electric current off from the electric motor and thereby stop the operation of the car.

The weight 15 is provided with ribs 15, 15 on its top side edge.

On a base 16 are pivotal supports 17 and 18 in which are pivoted angular levers 19 and 20 respectively. These levers are provided with arms, 19, 19 and 20, 20 respectively. These levers are normally supported in the positions shown. The arms are positioned at angles somewhat more acute than right angles, the shorter arms 19 and 20 having an up-turned inclinzuzion. Upon the upper free ends of each of the arms 19 and 20 is a latch member 19 and 20.

A laterally extending arm 20 carries an insulated circuit-closing plate 21, adapted to bridg the two insulated contacts 23-23, that are insulated and supported by the bracket, 24.

An automatic circuit opening switch 25 normally maintains the circuit rennin-fining the motor 9 closed.

A blade 26 is provided with a handle 27, and is pivoted as at 28. An open compression spring 29 tends to lift the blade 26. A coacting jaw contact 30 is a terminal where the switch closes the circuit. A latch 31 is carried by the handle part of the switch.

An electro-magnet 32 is provided with a pivoted, spring-pressed latching armature 33. The electro-magnet is in parallel circuit with the mains 35 and 36, by means of wires 37, 38, and 39.

The circuit through the electric motor is from the positive main. 35, through wire 10, through the motor 9, thence by Wire 41 to terminal at? of the switch, thence through blade 26, and jaw 30 to wire 39, thence to the negative main 36.

hen the counterbalancing weight 15 rests heavily on the arms 19 and 20*, as the result of the elongation of the cable, 8, the latch ends 15 and 15 of the arms 19 and 20*, are caused to pass over the respective ribs 15 and 15". thus securing and holding the weight in its depressed position, and preventing the descent of the car by the rotation of the de'energized armature of the motor, at the same time the lateral arm 20 is raised until the bridge 21 closes the electric circuit between the terminals 22 and 23, thus energizing the electro-magnet 32 which attracts its armature 33, releasing the switch blade 26, and opening the circuit including the electric motor 9 by spring 29. The motor is thereby disabled and the car is positively locked so that it cannot possibly descend until the automatic locking device has been opened.

\Vhile I have herein described in some detail a particular embodiment of my invention, it will be apparent to those skilled in the art that many changes in the details of construction and arrangement of parts might be made without departure from the spirit and scope of the invention and within the scope of the appended claims.

lVhat I claim is:

1. In an elevator safety device, the combination with an elevator cage, a counterbalancing weight therefor, and a motor, of means for engaging said weight to positively sustain the cage and to disable the motor.

2. In an elevator safety device, the combination with an elevator cage, a counterbalancing weight therefor, and an electric mo tor, of means for engaging said weight to positively sustain the cage and simultaneously opening the motor circuit.

3. In an elevator safety device, the combination with an elevator cage, a counterbalancing weight therefor, and an electric motor, of a pivoted weight-engaging arm adapted and arranged to be moved by said weight, and an electric switch included in circuit with the motor arranged to be opened by the movement of said arm.

at. In an elevator safety device, the combination with an elevator cage, a counterbalancing weight therefor, and a driving motor having a disabling means, of a part movable by the weight when it has reached a predetermined position in its possible movement, said part having two arms, one to engage the weight to lock it against further movement and the other to operate said motor-disabling means.

5. In a device of the character described, an elevator cage, a motor, a counterweight, and a part movable by abutment of the weight to engage said weight and disable the motor.

6. In a device of the character described, an elevator cage, a counterweight, and a part movable by abutment of the weight thereagainst to a position to obstruct the path of movement of said weight in either direction to lock said weight against further movement in either direction.

In testimony whereof I hereunto set my hand in the presence of two witnesses.

MARY F. ALLEN, W. LINN ALLEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Eaten,

Washington, D. C. 

